Optimization of a wave energy converter square array based on the differential evolution algorithm

The aim of optimizing wave energy converters (WECs) is to maximize the power output whilst reducing the cost of energy production. Here, the optimization of a square array composed of four identical cylindrical, heaving-buoy WECs is considered. Four optimization parameters, i.e., the radius and the draft of the buoy, the damping of the power take-off system, and the spacing of the WECs are considered. Two strategies are carried out to optimize the array in regular waves, and the performance of the optimized array in irregular waves is studied. The differential evolution algorithm is selected for the multi-parameter optimization. The higher-order boundary element method is used to simulate the interaction between waves and WECs according to linear potential flow theory. The array optimized by the second strategy extracts the maximum power, but its frequency adaptability is inferior to the array optimized by the first strategy. The optimized array in the first strategy can extract relatively large power from the irregular waves, whilst also exhibiting high energy capture efficiency. •Two strategies of array optimization are compared based on the DE algorithm.•The optimal array possessing the maximum power is unsuitable for irregular waves.•The array with appropriately small non-optimal buoy volume is practical.•The WEC array with large PTO damping has strong frequency adaptability.